Relatives say they believe the latest attack was revenge for her refusal to drop her complaint against the men, who they say were able to evade justice because they belonged to higher castes and had political connections.

"I will have to spend my entire life in constant fear of being raped again or killed," said the woman, who AFP is not naming for legal reasons.

"My life will never be the same. I am worried about my family's safety. They can harm us any time," she told AFP by telephone from her hospital bed in the northern Indian state of Haryana.

India promised to speed up rape trials in the wake of a fatal gang-rape in 2012 that shone a global spotlight on frightening levels of violence against women in India.

But rape and sexual assault remain commonplace and cases are often slow to come to court -- especially if the defendants are wealthy and well-connected.

Relatives of the victim said the alleged perpetrators of the 2013 rape had offered them money to withdraw the case, and threatened to attack her again if they did not.

"We were offered five million rupees ($75,000) to withdraw the case. They are rich people and have strong political links," her cousin told AFP.

"We didn't give in to their demands and pursued the case, but we were let down by the court, which gave them bail in May," he told AFP in the city of Rohtak in Haryana, where the family moved to after the first attack.

- 'Only rich get justice' -

He said he believed his cousin was originally attacked because she had spurned the advances of one of the alleged rapists.

"He must have thought, they are poor and helpless, and we will get away with the crime," he added.

The relative said police only moved to arrest the alleged perpetrators after weeks of protests by the Dalit community, who face widespread discrimination in India even though this is illegal.

"We were tossed from one police station to another, but no one was listening. The accused were bribing them and were getting all help from the authorities," he said.

"This country is only for rich and for upper castes, only they get justice," said the cousin, adding that the entire family had now converted to Buddhism to escape discrimination under the Hindu caste system.

Local police say they are using all their resources to track down another two men accused in last week's attack, and have set up a special investigation team.

"We are collecting all evidence and will investigate the case in a fair and transparent manner," Rohtak police chief Rakesh Arya told AFP.

But rights activists say the case shows the justice system is still failing victims of sexual assault, more than three years after the Delhi gang rape that sparked mass protests.

"We need action now to end this brutality that has become routine and to give the victims of violence the justice and protection they deserve," said Anju Malhotra, gender advisor to the UN children's agency UNICEF.